Synthesis of Stilbenecarboxylic Acids

Hager, George P.; VanArendonk, A. M.; Shonle, H. A.

doi:10.1021/ja01239a502

Cited by 7 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11, No. 10,1979 reactions increased in the following order: Mn<Co<Zn<iiW. The order was in accord with that of activity of catalysts for the polycondensation of BHET.…”

Section: Effects Of Catalysts On the Side Reactionssupporting

confidence: 77%

See 1 more Smart Citation

Formation of Aromatic Compounds as Side Reactions in the Polycondensation of Bis(2-hydroxyethyl) Terephthalate

Kamatani

Kuze

1979

Polym J

View full text Add to dashboard Cite

ABSTRACT:Studies on the side reactions in the polycondensation of bis(2-hydroxyethyl) terephthalate were performed in the presence of catalysts (Mn, Co, Zn, W). 4,4'-Biphenyldicarboxylic acid, l,2-bis(4-carboxyphenyl)ethane, and 2,4',5-biphenyltricarboxylic acid were found as major aromatic by-products in the reaction. The yield of these by-products was very poor in the absence of these catalysts, and remarkably increased in the presence of catalysts in the following order: Mn< Co< Zn <1; W. This order was in accord with that of the activity of catalysts for polycondensation of bis(2-hydroxyethyl) terephthalate. The side reactions were suppressed with the addition of radical inhibitor, indicating that the side reactions occurred with a radical mechanism; this was supported from ESR studies. The side reactio'ls are probably initiated by the alkyl radical ( -C6 H4 COOC2H4 ·) obtained from the reaction ofbis(2-hydroxyethyl) terephthalate with the metal of catalysts.KEY WORDS Bis(2-hydroxyethyl) Terephthalate / Poly(ethylene terephthalate) / Polycondensation / 4,4'-Biphenyldicarboxylic Acid / l,2-Bis(4-carboxyphenyl)ethane / 2,4',5-Biphenyltricarboxylic Acid / ESR / Free EXPERIMENT A-L MaterialsSeveral side reactions such as etherification 1 · 2 and thermal degradation 3 -6 have been observed in the polycondensation of bis(2-hydroxyethyl) terephthalate (BHET) or its oligomer. We found that 4,4'-biphenyldicarboxylic acid, 2,4' ,5-biphenyltricarboxylic acid, and 1,2-bis( 4-carboxyphenyl)ethane were obtained as by.products in the polycondensation of BHET. The side reactions sometimes lead to the deterioration of the physical and chemical properties of the poly(ethylene terephthalate) (PET) obtained. 2 · 3 · 7 In order to manufacture PET of high quality, details of the side reactions in the polycondensation must be investigated.BHET was prepared by the reaction of terephthalic acid with ethylene oxide. 9One of the present authors previously identified the mechanism of the polycondensation of BHET in the presence of catalysts (Co, Mn, Zn). 8 In this research, aromatic compounds formed by the side reactions in the polycondensation of BHET were determined quantitatively in the presence of a catalyst (Mn, Co, Zn, W); the mechanisms for the side reactions are discussed here.Catalysts (commercially available guaranteed grade) and a radical inhibitor, 1,3,4, Shell Fine Chemicals), were used without further prufication. Polycondensation of BHETPolycondensation ofBHET (1.5 mol) was carried out in a 1.0 dm 3 autoclave in the presence of a catalyst (0.3 mmol) at 273°C under reduced pressure. 8 Samples for the study of by-products were taken out of the autoclave at regular time intervals 8 and were subjected to methanolysis. Thermooxidative Degradation of PETThe polymer containing a polycondensation catalyst was powdered and heated for I h in an oven at 300°C under an air stream 4 -6 and was subjected to 787

show abstract

“…11, No. 10,1979 reactions increased in the following order: Mn<Co<Zn<iiW. The order was in accord with that of activity of catalysts for the polycondensation of BHET.…”

Section: Effects Of Catalysts On the Side Reactionssupporting

confidence: 77%

“…6 The products were recrystallized from acetic acid, mp 227-228°C (lit. 10 mp 227-228°C). A mixture of l,2-bis(4-methoxy-788 carbonylphenyl)ethylene ( 4.4 g, 0.015 mo!…”

Section: Preparation Of Authentic Samplesmentioning

confidence: 99%

Formation of Aromatic Compounds as Side Reactions in the Polycondensation of Bis(2-hydroxyethyl) Terephthalate

Kamatani

Kuze

1979

Polym J

View full text Add to dashboard Cite

show abstract

“…E -Stilbene-4,4 ‘ -dicarboxylic Acid. The method of Hager, Vanarendonk, and Shonle was followed . Yield: 2.90 g, 91%; mp > 320 °C (literature > 320 °C, literature 460 °C, sealed tube).…”

mentioning

confidence: 99%

Properties of a Stilbene-Containing Gemini Photosurfactant: Light-Triggered Changes in Surface Tension and Aggregation

et al. 2002

View full text Add to dashboard Cite

A new photosurfactant has been synthesized, and its photoreactions in water, interfacial properties, and changes in aggregation have been characterized. The compound is a stilbene-containing gemini photosurfactant (SGP), which is of interest because the headgroup spacer is a stilbene chromophore, and it may be prepared initially in the trans (E-SGP) form. Molecular simulations show that UV-induced reactions cause significant changes in molecular conformation and especially the relative orientation of hydrophobic chains. 1H nuclear magnetic resonance, UV−vis absorption, and liquid chromatography−mass spectroscopy results are consistent with photodimerization in aqueous solutions. Irradiation causes significant changes in surface tension (maximum Δγ = −12 mN m-1) and wettability (Δθ = −15° on hydrophobic glass). Furthermore, small-angle neutron scattering shows the initial E-SGP form is present as large vesicle-like aggregates whereas the UV-induced dimer gives small 20 Å spherical charged micelles. These results demonstrate the importance of molecular design for generating effective and efficient photosurfactants.

show abstract

“…trcms-4,4'-Dicarbomethoxystilbene was prepared from methyl a-bromo-p-toluate and 4-carbomethoxybenzaldehyde as shown in Scheme 2. The final recrystallized product had a melting point of 232-235 °C (mp 227-228 °C (Hager et al, 1944)). l,2-Bis(4-carbomethoxyphenyl)ethane was synthesize from frans-4,4'-dicarbomethoxystilbene by hydrogena- tion in methanol in the presence of a 10% palladium on carbon powder catalyst.…”

Section: Methodsmentioning

confidence: 99%